1. Technical Field of the Invention
This invention relates to telecommunication systems and, more particularly, to a mobile terminal and a method of connecting a computer network to a packet data network (PDN) over a single wireless link.
2. Description of Related Art
In the General Packet Radio Service (GPRS) network architecture, the xe2x80x9cMobile Terminalxe2x80x9d (MT) is the radio device handling the GPRS air interface. The xe2x80x9cTerminal Equipmentxe2x80x9d (TE) is the user equipment connected to the MT, and the xe2x80x9cMobile Stationxe2x80x9d (MS) designates both TE and MT together. In the Universal Mobile Telephony System (UMTS) architecture, the term xe2x80x9cUser Equipmentxe2x80x9d (UE) is equivalent to the GPRS MS.
In GPRS, the use of the Point-to-Point Protocol (PPP) to connect a single TE such as a laptop computer to an MT for the provision of wireless packet and Internet access has been well-documented in the UMTS standards UMTS 23.060 and UMTS 27.060. The PPP protocol uses two protocols, the Link Control Protocol (LCP) and the Network Control Protocol (NCP) to first establish the link between the TE and the MT, and then to provide a dynamic IP address to the TE. The way the technology and the standards are defined, however, they enable only one IP device to be connected through one cellular link.
In the current cellular packet data network technologies, such as GPRS/GSM (Global System for Mobile Communications), GPRS/EDGE (Enhanced Data Rates for GPRS Evolution), and UMTS, the network side can only associate a single host with each radio link between the Base Station System (BSS) and an MT. If more than one host is connected to the MT, the network is not able to handle this with only one packet data address association.
In the future, a user may carry a plurality of devices (for example, a Personal Digital Assistant (PDA), a laptop computer, a mobile telephone, etc.) that are capable of communicating with each other over a wired or wireless network. These devices may be connected to each other over a small Local Area Network (LAN) or a wireless LAN utilizing technologies such as Bluetooth, for example. It would be desirable to provide two-way connectivity to PDNs such as the Internet for all of the devices connected to the user""s LAN.
GPRS allows the MT to open up several Packet Data Protocol (PDP) Contexts at the same time. In the GPRS architecture, the MT is connected to one or more TEs through the defined xe2x80x9cRxe2x80x9d interface. However, each opened PDP Context requires a separate PPP stack in the MT in a one-to-one ratio, since PPP requires two unique endpoints for each opened session. Thus, a subscriber with a PDA and a laptop essentially requires two cellular links (and possibly two cellular subscriptions) to simultaneously connect both of the devices to the Internet.
With the advent of ad hoc networking, and with the important increase in bandwidth of the cellular PDNs based on EDGE and UMTS, it is expected that the capability to connect a network of computers through a single cellular link will become more critical. This is not possible today because the network assigns only one packet data address to the MS, and it is impossible for the PDN to associate with a TE if the TE does not have a unique address. When multiple TEs try to connect to the network through the use of only one MT, there is an insufficient number of address associations. The existing cellular packet data technologies allow associating many packet data addresses with the same host, but that is of no help in solving the problem here. No direct method based on ISO layer 2 and 3 technology can be used to solve this problem. In addition, there are no existing cellular protocols or IP protocols that can be used to solve the problem.
In order to overcome the disadvantage of existing solutions, it would be advantageous to have a mobile terminal and a method of connecting a plurality of devices with a plurality of IP addresses through the mobile terminal, and a single wireless link, to a packet data network (PDN) such as the Internet. The present invention provides such a mobile terminal and method.
In one aspect, the present invention is a method of connecting a plurality of devices, each having a unique IP address, through a single MT and a single wireless link to a PDN. The plurality of devices are connected to the MT on a network such as a LAN. In a first embodiment, the MT then requests and receives from the PDN, a network IP address comprising a plurality of unique individual IP addresses. The MT then utilizes, for example, a Dynamic Host Configuration Protocol (DHCP) server in the MT to distribute the plurality of unique individual IP addresses to the plurality of devices on the LAN.
In a second embodiment, rather than requesting a network IP address, the MT requests a separate PDP Context for each device on the LAN, and utilizes a PPP over Ethernet (PPPoE) session between the devices on the LAN and the MT to virtually separate the physical network connection into a plurality of unique individual IP addresses assignable to the plurality of devices on the LAN.
In yet another aspect, the present invention is an MT for connecting a plurality of devices, each having a unique IP address, through a single wireless link to a PDN. In a first embodiment, the MT includes (1) a Point-to-Point Protocol (PPP) stack for connecting the MT to the plurality of devices over a LAN; (2) means for receiving from the PDN a network IP address comprising a plurality of unique individual IP addresses; and (3) a DHCP server for distributing the plurality of unique individual IP addresses to the plurality of devices on the LAN.
In a second embodiment of the MT, the MT includes (1) means for requesting from the PDN, a separate packet data protocol (PDP) Context for each device on the LAN; and (2) a Point-to-Point Protocol over Ethernet (PPPoE) stack. The PPPoE stack connects the MT to the plurality of devices on the LAN, receives an indication from each individual device on the LAN whether the device requires an IP address, and distributes IP addresses to the plurality of devices on the LAN.